The engine type on the dirt bike is moulded on the crankcase under the output gearbox shaft.
Pit bike engines were all architecture inspired by the Honda Dax from the years 1970. The advantage is that the fixing points in the framework are all the same which ensures the perfect interchangeability.
LIFAN, the historic factory for pitbike engine : 88-147FMI, 125-1P52FMI, 120-1P52FMI-K, 125-1P54FMI, 138-1P54FMI, 1P55FMJ-140, 150-1P56FMJ
DUCAR, factory who sign early licensing with Honda but that was closed in 2009 : 125 - DJ154FMI, 140-DJ156FMI
Plant historically, JIALING Honda partner for the manufacture of Honda engines used on the Chinese market : 125-JH156FMI
YX, the factory which has imposed its pit bike engines to 90% of the market : 88-1P47FMI, 125 153FMI, 1P56FMJ 140, 149-1P56FMJ-5, 150-1P60FMJ
ZONGSHEN, a very large group with processes industrial very rigorous : 150 and 160 1P60YMJ
SHINERAY, factory specialized in vertical engine that works on the 250 cooling liquid since 2009. They manufacture engines and motorcycles, it is a heavy weight in industrial terms.
ZUNRUN, the last one open 2 years ago with a full new factory. The engineers come form YX and Zongshen. The good point is the boss like the motorbike race !